Refers to a female person, often used in contrast to 男子 (boy/man). Common in compound words like 女子学生 (female student) and 女子トイレ (women's restroom).
In this class, there are more girls than boys.
女子更衣室はあちらです。
The women's changing room is over there.
female fan who fantasizes about fictional characters
girls' night out; girls-only gathering